Mercury-arc-rectifier starting device



Jan. 31, 1928. 1,657,495

E. W. BREISCH MERCURY ARC RECTIFIER STARTING DEVICE Filed Dec. 7. 1921 ATTORNEY Patented Jan. 31, 1928.

UNITED STATES 1,657,495. PATENT OFFICE EDGAR W. BREISCI-I, F EDGEWOOD vPARK, PENNSYLVANIA, A SSIGNOB TO WESTING- HOUSE ELECTRIC 8c MANUFACTURING COMPANY, A CORPORATION 01 PENNSYL- VAN IA.

MERCURY-ARC-BECTIFIER STARTING DEVICE.

Application filed December 7, 1921. Serial No. 520,618.

My invention relates to vapor electric apparatus and particularly to means for initially starting such apparatus.

In mercury converters heretofore employed,

a rather elaborate startin arrangement has been utilized, and even with this provision, difliculty has sometimes been encountered in securing the automatic starting of the converter after a temporary failure of the supply voltage when the back electromotive force of the direct-current load is. relatively high, leaving a considerably reduced effective voltage between the anode and cathode.

An object of my invention is, therefore,

to provide a cheap and eflicient automatic starting system for vapor converters, such, for example, as mercury arc converters, which admits of operation on low effective voltages.

Other objects of my invention, as well as details of construction, whereby my invention may be practiced, will appear more fully in the following description of the nature, mode of operation and the applications of my invention.

According to my invention, I provide, in a well-known type of converter, an auxiliary starting electrode, which is normally immersed in the main cathode and which is adapted to be rendered electrionically active upon a slight tilting of the converter, there- .by resulting in the formation of an are between the starting electrode and the anode. The are thus formed is readily transferred to the main cathode upon the rectifier being returned to its initial position.

.The single figure of the drawing is a diagrammatic view of circuits and apparatus embodying my invention.

In the drawing, a mercury-arc converter 1 is shown as comprising an enclosing en velope 2 having main anodes 3 and 4 and a main cathode 5,-preferably of mercury, contained therein. The converter 1 is pivotally mounted upon a bearing member 6 which may be sup orted in any approved manner. An auxiliary filamentary starting cathode 7 is connected by conductors 8 and 9 to circuit terminals 10 and 11, respectively, the several elements being so disposed as to be normally immersed in the liquid.

Upon a slight tilting of the tube, however,

suflicient to cause the mercury to assume the postion indicated by the dotted line, the

auxiliary cathode 7, conductor 9 and circuit magnet 24 are serially included in circuit terminal 11 are uncovered, thereby ermitting the excitation of the. main cat odev 5, as hereinafter described. The anodes 3 and 4 are connected, respectively, by conductors 12 and 13 to opposite terminals of a secondary winding 14 of a transformer 15, the primary winding 16 of which is connected by conductors 17 and 18 to a source of alterhating-current energy (not shown), A 0011- ductor 19 extends from the terminal 10, which is connected to the main cathode 5, to an intermediate tap point 21 on the transformer winding 1. 1. A direct-current load 22 and an actuating winding 23 of a tilting with the conductor 19.

A tilting lever 25, which is ri 'dly secured to the converter envelope 2, as one end thereof pivotally connected, by means of a link 26, to a movable core member 27 of the tilting magnet 24;. The lower end of said core member carries a switch member 28 which coacts with stationary contact members 29 and 31 to eflect the energizationof the hot cathode 7 when the converter is tilted suificiently to uncover the hot cathode 7, the conductor 9 and the circuit terminal 11, as indicated by the dotted line in the drawing. An exciting circuit for the cathode 7 extends from the circuit terminal 11 through stationary and movable contact members 29, 31 and 28, respectively, of the tilting magnet 24 and a portion 32 of the secondary winding 14 of the transformer 15 to the main cathode circuit terminal 10.

The converter is normally held in tilted position by means of a weight 33 mounted on the lever 25. When the primary windin 16 is energized, as by the closing of a switc 34., which is serially included in the conductor 18, the filament 7 is heated, thereby causing the establishment of an are between the filament 7 and the anodes 3 or 4. The solenoid 24 is thereupon energized totilt the converter to an upright position thus causing the filament 7 to be immersed and hence the transfer of the arc to the main cathode 5.

-Under favorable conditions, the arc may immediately .shift to the mercury cathode 5 as soon as the filament 7 is energized and before the converter has had time to tilt to an up right position.

lhhave thus provided for the automatic starting of a mercury-arc converter upon the energization of the alternating-current supply line. An additional advantage of im mersing the filament 7 in the mercury cathode 5 during normal operation resides in the the applications thereof, it is capable of various changes and modifications without dearting from the spirit of my invention and desire, therefore, that only such limitations shall be imposed thereon, as are spe cifically set forth in the appended'claims.

I claim as my invention:

1. In an evacuated electric apparatus, a container, a pair of electrodes forming a space-current path contained therein, one of said pair of electrodes being of a liquid vaporizable material an electron-emitting element immersed in said vaporizable electrode, and means for, at times, exposing said electron-emitting element.

2. In an evacuated electric apparatus, the combination with a container, of an anode and a liquid cathode disposed therein, and an auxiliary cathode having an electronemitting portion immersed in said liquid cathode and means for tilting said container, said electron-emitting portion being exposed upon tilting of said container.

3. In an evacuated electric device, the combination with an enclosing envelope, of an anode and a liquid cathode disposed therein, a tiltable mounting for said envelope, an auxiliary solid cathode having an electronemitting portion normally immersed in said liquid, said electron-emitting portion being exposed when said envelope is in its tilted l position, and means for exciting said auxiliratus for immersing and deenergizing said electron-emitting portion.

6. The combination with a mercury-vapor rectifier, of a heating member normally immersed under the active surface of the mercury, means for, at times, exposin said heating member over the active surIace of the mercury and means for energizing said heat in member.

I. The combination with a mercury-va or space current device, of an auxiliary amentary cathode immersed in the mercury and means, responsive to the operating conditions of said rectifier, for exposing said filamentary cathode from the mercury.

8. The combination with a mercury-vapor rectifier, of an auxiliary filamentary cathode normally immersed in the mercury during the normal 0 eration of the rectifier, means for biasing t e rectifier to a tilted position, said filamentary cathode being so disposed as to be exposed upon the tilting of said rectifier, means for energizing said filamentary cathode and means responsive to the establishment of an are for tilting the rectifier to normal operating position.

9. In a space-current device, an anode, a solidelectron-emitting electrode, a liquid, and means for causing said liquid to cover and expose said electrode.

10. A space current device comprising a liquid electrode, an auxiliary electrode having an electron emitting portion, means responsive to the current through said device for exposing said electron emittin portion and for immersing it in said liqui and for energizing and deenergizing said electron emitting portion.

In testimony whereof, I have hereunto subscribed my name this 25th day of November, 1921.

' EDGAR W. BREISCH. 

